I think we can argue this for the next couple of months, but ultimately all sites should be chronoing at the start of the day, on one weight, probably 0.20, and be prepared to have marshals do random on the spot checks using the same weight, especially if particular players have history or complaints made against them.
End of the day, cheats WILL cheat, they'll use everything they can to achieve what the perceive to be an advantage over their fellow players, hpa, npas, quick change springs etc all enable them to make short notice changes to energy output after the chrono, & sites can't stop them, but they're letting down their honest clients by not trying their hardest to root out the cheats, & when found they should be very publicly banned.
Any site that does that, I'd play there, as was said earlier, it's all about trust so any site that works hard to push that agenda gets my vote.